If anyone else is stuck with this, here's what helped me. Changing the Anchor settings did not work for me. I am using datagridviews within groupboxes in a form which is inside a parent form.
Handling the form resize event was the only thing that worked for me.
private void Form1_Resize(object sender, EventArgs e)
{
groupBoxSampleQueue.MinimumSize = new Size((this as OperatingForm).Width - 22, 167);
groupBoxMachineStatus.MinimumSize = new Size((this as OperatingForm).Width - 22, 167);
}
I added some raw numbers as buffers.